Myth: It’s an error to split infinitives
An infinitive is one uninflected form of a verb, and it’s easy to spot. To go, to say, to wonder, to ride, to share—these are all examples of infinitives, and you will recognize plenty of them in your own writing, no doubt. Usually (though not always), and infinitive verb is preceded by “to.”
To split an infinitive is to put a word or words between “to” and the verb in order to modify that verb. Again, the myth of this error comes to us as dogmatic prescriptive advice, gaining a foothold in mid-nineteenth century England’s insistence that English should emulate Latin (in Latin, infinitives are a single word and cannot be split).
Example of split infinitive:
“To boldly go where no one has gone before”
In this case, “boldly” (an adverb) modifies “to go” (an infinitive). This excerpt from the speech that opens Star Trek: The Next Generation splits the infinitive to get the right rhythm; neither “boldly to go” nor “to go boldly” feel quite as emphatic or, well… “bold,” do they?
But there are far better reasons to split infinitives than for rhetorical effect. Sometimes the split infinitive presents the clearest phrasing. Consider a sentence without a split infinitive: “She needed to assist further efforts in the area.”
Do we mean that she will give more assistance or that she will assist later efforts? Let’s rephrase, still avoiding the split infinitive: “She needed further to assist efforts in the area.”
The ambiguity is not lessened here. Do we mean that she now has greater need to assist or that she has the need to give more assistance?
If we mean that she needs to give more assistance, it’s clearest to split the infinitive with “further”: “She needed to further assist efforts in the area.”
Other examples show different circumstances in which the split infinitive is preferable, and you can easily search these out. In some cases the split will be nearly unavoidable (e.g. “He understood her wish to more than pass by that island paradise”).
I should stress that the split infinitive is not always a good stylistic choice, and as with every decision you make in your writing, you should be deliberate in your decision to split infinitives. Sometimes, though, it is the best or only choice you can make, so the longstanding ban on split infinitives can be safely ignored.
This article is part of Writing myths: The reasons we get bad advice.
This discussion of split infinitives owes much to Amy Einsohn’s book, The Copy Editor’s Handbook, specifically her discussion of both split infinitives and Theodore Bernstein’s take on them in his own book, The Careful Writer.